Currently, there are two means of preventing false operations on electric equipment. One makes use of the linkage relations between the locks (or by means of key-exchange), which is specified as follows: suppose there are three sets of equipment A, B and C, which are operated in sequence of A, B and C strictly, the three sets of equipment are respectively installed with program-locks indicating the sequence; during operation, only when the program-lock installed on the equipment A is unlocked can the equipment A be operated; what's more, only after the operation of the equipment A is completed, can the key for the program-lock installed on the equipment B be obtained to unlock the program-lock, and then can the equipment B be operated. By this means, the operations are performed in sequence of A, B and C strictly. The other means is performed by computer, of which the operation sequence of equipment is built in the key to the computer and the operations are performed strictly in sequence by means of the key. But these two means both have defects. With respect to the first means, the relations between the equipment are expressed in terms of relations between the locks, which lacks flexibility. What's more, when there are more sets of equipment and the logic relationship is complex, much more locks need to be installed and much more logic processes of key-exchange are needed. Furthermore, the physical locks are easily damaged by natural factors such as corrosion, and have high damage rate and breakdown rate. If one of the locks can't work, the subsequent operations will be influenced. With respect to the second means, the logical relations between the equipment are stored in the key to the computer in form of data. The locked state of the lock ensures the equipment not to be operated, but no or only part of the state information of the locks is exchanged between the locks and the key to the computer, which makes the key to the computer can't correctly acquire the present state of the equipment in operation, so that the operation for some equipment in the sequence of operations might be left out, and some false operations may occur.